Wrap shared object in a class to control its loading (#2637)

* Wrap shared object in a class to control its loading

* Fix libwarpx attribute references

* Updated callbacks.py for updated libwarpx

* Removed the wx module plus other clean up

* Further revision of how to use the pywarpx module.

Now, _libwarpx should not be imported by external scripts except in special circumstances.

* Updated documentation

* Clean up end of line whitespace

* Added more wrapping routines plus some clean up

* Fixed use of pywarpx in two examples

* Fix for getistep

* Fixed for the EB Python interface

* Silence a warning for our wrapper

Co-authored-by: Axel Huebl <axel.huebl@plasma.ninja>

2 files changed, 14 insertions, 17 deletions

diff --git a/Examples/Tests/ParticleDataPython/PICMI_inputs_2d.py b/Examples/Tests/ParticleDataPython/PICMI_inputs_2d.py
index 6ed144dbc..2162236eb 100755
--- a/Examples/Tests/ParticleDataPython/PICMI_inputs_2d.py
+++ b/Examples/Tests/ParticleDataPython/PICMI_inputs_2d.py
@@ -1,10 +1,9 @@
 #!/usr/bin/env python3
-
-from pywarpx import picmi
-import numpy as np
-
 import argparse
 import sys
+import numpy as np
+import pywarpx
+from pywarpx import picmi, callbacks
 
 # Create the parser and add the argument
 parser = argparse.ArgumentParser()
@@ -106,11 +105,10 @@ sim.initialize_warpx()
 # python particle data access
 ##########################
 
-from pywarpx import _libwarpx, callbacks
 
-_libwarpx.add_real_comp('electrons', 'newPid')
+pywarpx.add_real_comp('electrons', 'newPid')
 
-my_id = _libwarpx.libwarpx.warpx_getMyProc()
+my_id = pywarpx.getMyProc()
 
 def add_particles():
 
@@ -124,7 +122,7 @@ def add_particles():
     w = np.ones(nps) * 2.0
     newPid = 5.0
 
-    _libwarpx.add_particles(
+    pywarpx.add_particles(
         species_name='electrons', x=x, y=y, z=z, ux=ux, uy=uy, uz=uz,
         w=w, newPid=newPid, unique_particles=args.unique
     )
@@ -142,11 +140,11 @@ sim.step(max_steps - 1)
 # are properly set
 ##########################
 
-assert (_libwarpx.get_particle_count('electrons') == 270 / (2 - args.unique))
-assert (_libwarpx.get_particle_comp_index('electrons', 'w') == 0)
-assert (_libwarpx.get_particle_comp_index('electrons', 'newPid') == 4)
+assert (pywarpx.get_particle_count('electrons') == 270 / (2 - args.unique))
+assert (pywarpx.get_particle_comp_index('electrons', 'w') == 0)
+assert (pywarpx.get_particle_comp_index('electrons', 'newPid') == 4)
 
-new_pid_vals = _libwarpx.get_particle_arrays(
+new_pid_vals = pywarpx.get_particle_arrays(
     'electrons', 'newPid', 0
 )
 for vals in new_pid_vals:
diff --git a/Examples/Tests/ParticleDataPython/PICMI_inputs_prev_pos_2d.py b/Examples/Tests/ParticleDataPython/PICMI_inputs_prev_pos_2d.py
index d8e37140f..d71aa3fea 100755
--- a/Examples/Tests/ParticleDataPython/PICMI_inputs_prev_pos_2d.py
+++ b/Examples/Tests/ParticleDataPython/PICMI_inputs_prev_pos_2d.py
@@ -3,6 +3,7 @@
 # --- Input file to test the saving of old particle positions
 
 import numpy as np
+import pywarpx
 from pywarpx import picmi
 
 constants = picmi.constants
@@ -109,12 +110,10 @@ sim.step(max_steps - 1)
 # exist
 ##########################
 
-from pywarpx import _libwarpx
+assert (pywarpx.get_particle_comp_index('electrons', 'prev_x') > 0)
+assert (pywarpx.get_particle_comp_index('electrons', 'prev_z') > 0)
 
-assert (_libwarpx.get_particle_comp_index('electrons', 'prev_x') > 0)
-assert (_libwarpx.get_particle_comp_index('electrons', 'prev_z') > 0)
-
-prev_z_vals = _libwarpx.get_particle_arrays(
+prev_z_vals = pywarpx.get_particle_arrays(
     'electrons', 'prev_z', 0
 )
 for z_vals in prev_z_vals: